The present invention relates generally to the interconnection of roof panels and the securement of the roof panels to a supporting structure.
More particularly, the invention relates to a clip device and joint construction which will provide superior pull-up strength and increased resistance to failure resulting from thermal expansion and contraction of commonly used corrugated metal roof panels.
The type of roof construction considered in this invention may typically be secured to the purlin supporting structure by a direct application of a threaded fastener through a portion, preferably the valley of the corrugation and into the purlin. This obviously produces a joint which is inherently difficult to seal from moisture. The joint just described will also not permit thermal expansion or contraction of the roof panels without tearing or otherwise deteriorating the roof panel in the area of the fastened joint.
Other prior art joint constructions utilize a hold-down clip device which is interleaved between abutting and crimped lips on adjacent work panels. The clip is secured directly to the purlin by utilizing an attaching flange portion with a threaded fastener extending through and clamping this flange to the purlin. This type of joint construction has also been found to be deficient in resisting harmful effects of thermal contraction and expansion in addition to certain weaknesses in pull-out strength.